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authorJoe Thornber <ejt@redhat.com>2013-11-08 17:36:17 +0100
committerMike Snitzer <snitzer@redhat.com>2013-11-11 17:37:50 +0100
commit532906aa7f9656209f30f08dfadd328fc1bc6912 (patch)
treed8af8f44e38894c97a0d891152723d5b7184edc5 /drivers/md/dm-cache-policy.h
parentdm cache policy mq: reduce memory requirements (diff)
downloadlinux-532906aa7f9656209f30f08dfadd328fc1bc6912.tar.xz
linux-532906aa7f9656209f30f08dfadd328fc1bc6912.zip
dm cache: add remove_cblock method to policy interface
Implement policy_remove_cblock() and add remove_cblock method to the mq policy. These methods will be used by the following cache block invalidation patch which adds the 'invalidate_cblocks' message to the cache core. Also, update some comments in dm-cache-policy.h Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to '')
-rw-r--r--drivers/md/dm-cache-policy.h21
1 files changed, 17 insertions, 4 deletions
diff --git a/drivers/md/dm-cache-policy.h b/drivers/md/dm-cache-policy.h
index 33369ca9614f..052c00a84a5c 100644
--- a/drivers/md/dm-cache-policy.h
+++ b/drivers/md/dm-cache-policy.h
@@ -135,9 +135,6 @@ struct dm_cache_policy {
*/
int (*lookup)(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock);
- /*
- * oblock must be a mapped block. Must not block.
- */
void (*set_dirty)(struct dm_cache_policy *p, dm_oblock_t oblock);
void (*clear_dirty)(struct dm_cache_policy *p, dm_oblock_t oblock);
@@ -159,8 +156,24 @@ struct dm_cache_policy {
void (*force_mapping)(struct dm_cache_policy *p, dm_oblock_t current_oblock,
dm_oblock_t new_oblock);
- int (*writeback_work)(struct dm_cache_policy *p, dm_oblock_t *oblock, dm_cblock_t *cblock);
+ /*
+ * This is called via the invalidate_cblocks message. It is
+ * possible the particular cblock has already been removed due to a
+ * write io in passthrough mode. In which case this should return
+ * -ENODATA.
+ */
+ int (*remove_cblock)(struct dm_cache_policy *p, dm_cblock_t cblock);
+ /*
+ * Provide a dirty block to be written back by the core target.
+ *
+ * Returns:
+ *
+ * 0 and @cblock,@oblock: block to write back provided
+ *
+ * -ENODATA: no dirty blocks available
+ */
+ int (*writeback_work)(struct dm_cache_policy *p, dm_oblock_t *oblock, dm_cblock_t *cblock);
/*
* How full is the cache?